Protecting the oral mucosa in patients with oral tongue squamous cell carcinoma treated postoperatively with intensity-modulated radiotherapy: a randomized study

Abstract

Objectives/hypothesis: Is the severity of acute oral mucositis in patients who receive postoperative intensity-modulated radiotherapy (PO-IMRT) for oral tongue squamous cell carcinoma (SCC) reduced by sparing the oral mucosa outside of the planning target volume (PTV)?

Study design: Prospective, randomized trial.

Methods: Forty-eight patients with oral tongue SCC who received PO-IMRT at our institution were randomized to two groups: the oral-sparing (OR-SP) group and oral-unsparing (OR-USP) group. For the OR-SP group (n = 24), the oral mucosa outside of the PTV was spared. Furthermore, the mucosa including the bilateral cheeks, upper lip, and lower lip was defined as the united site and given <32 Gy. For the OR-USP group (n = 24), none of the oral mucosa was protected. The severity of clinical acute mucositis in each patient was assessed weekly during PO-IMRT until completely healed. Oral mucositis was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Dosimetry and therapeutic measures related to acute mucositis between the two groups were compared.

Results: During PO-IMRT, no patient experienced grade 4+ acute mucositis in any oral site. Compared to the OR-USP group, there was less grade 2 and 3 mucositis in the united site of the OR-SP group (0% and 25% vs. 45.8% and 54.2%, respectively; P = .000). Also, the mean dose to the united site was significantly lower with OR-SP compared to OR-USP (41.8 ± 7.4 Gy vs. 58.8 ± 2.2 Gy; P = .000). The OR-SP group was associated with significant reductions in the use of analgesics (P = .043) and intravenous antibiotics (P = .039). No recurrences were detected in the vicinity of the spared oral mucosa (the united site) during a median follow-up time of 30 months.

Conclusions: OR-SP PO-IMRT for patients with oral tongue SCC resulted in a significant decrease in the severity of acute mucositis and improved quality of life. The sparing of the oral mucosa outside of the PTV is safe and does not compromise oncologic outcomes.